Method of and apparatus for drying fruits, vegetables, and other substances



l G. H. BENJAMIN. METHOD 0F AND APPARATUS FOR DRYING FRUITS, VEGETABLES,AND OTHER SUBSTANCES.

` AIfLlCATIU.. FILED APR. 16. |917. 1,839,092. Patented May4, 1920.

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G. H. BENJAMIN.

METHOD 0F AND APPARATUS FOR DRY'ING FRUITS, VEGETABLES, AND OTHERSUBSTANCES. APPLICATION FILED APR. 15| |917.

1,339,092. Patented May 4, 1920.

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GEORGE HILLARD BENJAMIN, F NEW YORK, N. Y.

METHOD OF AND APPARATUS FOR DRYING FRUITS, VEGETABLES, AND OTHERSUBSTANCES.

' Appucation mea April 16,

To all 'whom it may concern.'

Be it known that I, GEORGE HILLARD BENJAMIN, a citizen` of the UnitedStates,

New York, 1n the county and State of New York, have inventedcertain newand useful Improvements in Methods of and Apparatus for Drying Fruits,Vegetables, and other Substances, of which the following is aspecification.

. Many bodies which it is desired to dehydrate, cannot be successfullyhandled by placing such bodies upon fixed traysor mov- .ing belts andsubjecting them to moving air currents and for the following reasons:Where the body to be treated is in a finely divided or comminuted form,the air currents pick up the body and either carrygit out of theapparatus, or deposit'it in situations in the apparatus, whereitsaccumulation is objectionable.

Where the material acted upon is oney which, during treatment, exudesits moisture and becomes gummy, it usually packs,A where trays are used,and where moving belts are used, spreads over the edges of the belts andgums them up, interfering with the action of the belts and the apparatusas a whole.

To avoid the above objections, as well as others, I have designed theapparatus illustrated and described in this specification, and whichconsists essentially of an inclosing casing divided into two horizontalzones communicating at one end, a'V system of supporting rails carriedthrough the zones, a series of baskets adapted to move over the rails,means for moving the baskets progressively through the zones over therails,' and means for causing heated air currents to be delivered intothe apparatus, move through the zones and out of the' apparatus.

In the-dehydration of many substances, it is' found that where the bodyacted on .is subjected to heated air currents, the exudation of water isvery rapid when the body is first subjected to the air currents, butdecreased as the body is moved through the apparatus, usually for tworeasons: First,

Speciflcation of Letters Patent. j

. and time may Patented May 4, 1920.

1917. Serial No. 162,252.A

the body acted on by a given temperature is decreased progressively intime.

In order to avoid the objections above stated, I arrange to boost thetemperature of the air currents after they have passed over the bodytraversing the upper zone of the apparatus and before traversing thelower zone. By this means' absorbing capacity of the introduced aircurrents uniform throughout the apparatus, or I may increase thetemperature and the absorbing value of the air currents transmitted overthe lower zone, in accordance with the decrease in the exudation ofWater from the body acted on as it passes through the lower zone. It hasfurther been `'observed that in subjecting bodies to the action ofdehydrated air in an inclosure in which the hot airis introduced in onezone and drawn out at another, that the air as it absorbs moisturedecreases in specific gravity and accumulation in the top of theapparatus. Further, that such air, z'. e., moisture saturated lorpartially saturated` I preserve the y becomes in a senseI dead; that is,decreases in molecular velocity. By experiment have discovered that ifsuch moisture laden air is caused to pass within the influence of 'therays transmitted from an electric light, that such rays will impartmolecular motion to the moisture laden air, and that the degree ofmolecular motion or its character may be variously modilied by means ofscreens, which act to diminish the light transmitted, 4or -vary thecolor of the light.v I have' further discovered that by varying thelight and the color of the light, the physical effects of the light uponthe material under treatment may be varied` thus the degree of'exudation per unit of temperature be varied; the color of the materialmay be altered; the character of the gases evolved from the materialunder treatment may be changed: the physiological effects of thematerials of which the body acted on is composed, may be'varied; thus,for instance, the conversion of reserve food products into sugar,maltosev and the like. may be effected, and very many other resultsobtained which are not possible where the body is subjected only to,

yheat and moisture, the effects in some c ases being duel to thecatalytic effects ofthe light rays.

The accompanying drawings will serve to illustrate the general featuresof an apparatus which embody my invention and through which my improvedmethod may be carried into effect, in which Figure 1 is a verticalsection; Fig. 2 a horizontal section taken on the line H-II of Fig. 1;Fig. 3 a vertical section corresponding to Fig. 1 showing the parts in adifferent position; Fig. 4 a transverse section on the line IV-IV ofFig. 1; Fig. 5 a transverse section on the line V-V of Fig. 1, and Fig.6 an enlarged view of parts of the mechanism for feeding the baskets tothe apparatus.

In the drawings, 5 represents a suitable casing arranged horizontally.In this casing, and about midway of the vertical height, is a partition6. This partition eX- tends from the left hand end of the casing' towardthe right hand end, but leaving aspace indicated by 7, by which the twohorizontal zones marked respectively A and l5 within the casing,communicate. The zone A of the casing, communicates with an inlet airpassage 8; zone B of the casing with the eduction orice 9 of a blower10. The air drawn into the 4casing through 8, passes through the zone Aby passage 7 to zone B, and out through the blower 10.

Situated in zone A4 is a steam coil or other form of supplemental heater11, and stuated in the space 7 between the zones A and is a steam coilor otherform of supplemental heater 12. Situated in the zone A areelectric lights 13 and 14, spaced along the casing. Below these lightsare arranged screens 15 and 16. These screens are removable and can beformed of any material and of any color as desired, according to theef,- fect it is desired to obtain through the electric lights and thescreens.

Situated in the zone A, and about midway, are a pair of rails 17. Theleft hand ends of these rails extend into tne passage way 8 and coact ina manner hereafter described with a pair of inclined` rails 18 in suchpassage way. The right hand ends .of

the rails 17 are turned downward as shown at 19. Situated in the zone B,are a pair of rails 20. The left hand ends of these rails extend into apassage way 21. The right hand ends of these rails are turned upward asshown at 22, and in such manner that the will lap the right hand ends 19of the rai s 17, in the zone A, but leave a sulicient .distance betweenthem for the passage of the wheels carrying the baskets, as willhereafter be explained.

Arranged to move over the rails 17,18 and 20 through rollers 23, arebaskets 24. These baskets are preferably formed of a reticulate material25, so as to allow the air cur` rents and light to penetrate thematerial i-n the baskets. The baskets are designed to move progressivelythrough the apparatus,

being introduced through the passage way 8 into the zone A, then passingdownward to move through the zone B, and out of the apparatus throughthe passage way 21.

Very many devices may be employed to effect the progressive movement ofthe baskets through the apparatus. That employed consists in a pair ofsprocket wheels 26,-27, carrying an endless chain 28 driven by4 pulley29. The endless chain 28 is provided with spaced projections 3() adaptedto coact with horizontal aXles 31 on which the rollers 23 rotate, andthus as the chain moves forward it moves the baskets forward through thezone. When the rollers reach the end of t-he rails 17 they are receivedin hooked projections 32 on wheel 26 and thus carried downward to bedelivered upon rails 20 and move over rails 20 toward the left to bedelivered into the passage way 21. Movement ofthe baskets along therails 17 from left to right, and along the rails 20 from right to left,is` as above described,

provided by the sprocket wheels and chain. Movement of the baskets intothe zone A and on to the rails 17 and out of the zone B into the passage21, is provided by the following described mechanism: At the lefthandend of the passage 8 is a pivoted door 33 which, when closed, takesthe position shown in Fig. 1, closing the passage 8 and opening thepassage 34 from the air supply, and when open, takes the position shownin Fig. 3, opening the passage 8 and closing the passage 34 from the airsupply.. Arranged within the passage 8 are the rails 18.

When the basket with its rollers is introduced into the passage 8, thebasket tends to move by gravity down the rails 18 andon to the rails 17.o provide that the motion downward shall be a step by step motion,

'there are provided two sets of checking levers 35--36, pivoted to theside frame of the casing` on each side of the rails 18. These levers areprovided with upwardly projecting members 37-38-3940 which coact withthe horizontal axle`s'31. The lower lever of each of the series 35 isprovided with a bell-crank extension 41, which is con nected by a link42 to a lever 43 having a horizontal shaft 44 which is journaled in albearing 45. The lower lever ofeach ol the series 36 is connected byalink 46 to the lever 43. By means of a spring 47 connected to bell-crank41 and acting on link 42, the lever 43 is moved to rest against astationary support 48, thereby causing the levers 35 and 36 to be movedto the position shown in Fig. 3. When lever 43 is in this position, theaxle 31 of-a basket H rests against an upwardly extending arm 49 of aU-shaped extension of lever 43, the axle 31 of a basket I rests againstthe projection 38 of one of the levers the axle 31 of a basket J restsagainst the projection 39 of one of the levers 36; and the axle 31 of abasket K rests against the projection 38 of one of the levers.35. Theother, arm 50 of the U-shaped extension of. lever 43 extends upward inline with the side of axle 31 opposite to that of arm 49. 3l of basket Hstands in line with the center of shaft 44. J

Mounted on each support 48 is a reciprocating slide .51 having a hook,pawl 52 pivotedA thereto and supported by meansof a 4stop 53. W'henslide 51 moves toward the left, it moves under the lever 43, therebycauslng movement of the lever and parts' connected thereto from theposition shown in Fig. 3 to the position shown in Figs. 1 and 6. Thismovement of lever v43 causes movement of arm 49 downward away from axle31, and upward movement of arm 50 against the axle 31, thereby holdingthe axle during movement of the hook pawl 52 into.

engagement with the axle. l By reference to Fig. 1, it will be seen thatthe axle of basket I has moved to rest against the projection 40 of oneof the levers 36; the axle of basket 'J has moved to rest against theprojection 37 of one of the levers 35, and the axle of basket Khas movedto rest against the projection 40 of one of the levers 36. A basket Lmay have been introduced and its axle brought to rest against theprojection 37 of one of the levers 35. When in this position,`

the horizontal axles 31 are caught by hook pa-wls 52 and drawn to theright, on to the rails 17, and into a position to coperate with theupward projections 30 on the chain 28. The movement of the hook pawls 52and slides 51 to the right, is effected by means of levers 54 securedtoa shaft 55, when connected through an arm 56 and a link57 connected to acrank arm 58 forming part of a small gear wheel 59 which rotates on ashort shaft 60. Gear wheel 59. is in mesh with a large gearwheel 61secured to the shaft 62 to which the chain wheel 27 is secured. Therelation of the gears 59 and 61 is such that when the gear 61 makes onesixth of a revolution, the pawl 52 will be moved from vthe positionshown in Fig. 3 to the position shown in Fig. 1, and back to theposition shown in Fig. 3, carrying a basket so that its axle stands infront of a projection 30 of chain 28. The oscillating movement of levers54 also causes reciprocating movement of slides 63 on stationarysupports 64. Pivoted 011 each slide 63 is a pawl 65 which is supportedby means of' a stop 66, which, when a basket reaches the position M inzone B, takes against the horizontal axle 31 and pushes the basket tothe left into the passage way 21` 67-68 represent sliding doors whichcontrol the passage way 21.

The operation of the device is as follows: The door 33 having beenclosed, heated air from any desired source is transmitted The center ofthe axle l greater than through zone A, to passage 7 through zone B toeduction orifice 9 of the blower 10. As the air passes through theapparatus, the supplemental heat may be imparted to it b the coils 11 or12 or both, as may be desire At the same time the electric current isturned on tothe electric lights 13 or 14 or both, the wheels 26-27 setin motion whereby the baskets 24 will be fed step by step to the passage8 and progressivel moved throu h the zones A and to be elivered out othe` apparatus through the passage way 21,- the door 67 at such timebein yopen and the door 68 closed. The object o using the doors, 33,67and 68 is toprevent ingress of atmospheric air into the apparatusduri-ng the 4time the baskets are fed linto and out of the apparatus.

It will be observed that the air introduced into zone A is the'hottestand therefore has and the air passing through zone B is the coolest andhas the least capacity for absorbing moisture; that is, supposing thesupplemental heater 12 is not in use. By means of supplemental heater12, air passing from zone A to zone B can be brought to the originaltemperature or .boostedv above the original temperature, so that itsabsorbing capacity for moisture in zone B is in zone observed that bymeans of the electric lights in zone A (and similar lights may be placedin zone B if desired) the molecular velocity It will be furtherv withthe molecules of the air current may j be increased over that normal tothe molecules at the temperature originally given tok the molecules.Further, the chemical or catalytic effect of the light may be exerted onthe material under treatment during the whole time that the material ispassing through the zone A, and by the use of similar-supplementalapparatus, through the zone B.

Having thus described my invention, I claim:

1. The method of partially dehydrating bodies, which consists insubjecting them to the simultaneous action of radiant heat, electriclight rays of controlled intensity, and a moving drying medium having acontrolled temperature and humidity.

2. The method of partially dehydrating bodies, which consists insubjecting the portion of the body having the greatest amount ofmoisture to the' action of air currents having an initial temperatureand percentage of humidity, then heating said air currents to compensatefor the loss of temperature occurringv in passing over such portion ofthe body, and then transmitting the same air bodies, which consists incausing heated air currents to pass over the body and within the inuenceof electric light rays,- then boosting the temperature of the aircurrents, and finally causing the boosted air currents to pass over asimilar body under treatment.

4. The method of increasing the molecular velocity of heated aircurrents carrying water, over the original velocity of such heated aircurrents carrying a less amount of water, which consists in causing theheated currents carrying the larger amount of water to pass within theinfluence of electric light rays.

5. In an apparatus of the class described, the combination of aninclosing casing, a horizontal partition for dividing the apparatus intotwo. sections, means' for feeding heated air into one of said sections,means for discharging the heated air from the other of said sections,and means for projecting electric light rays into the moving heated air,whereby the molecular velocity of the heated air during the time it istraversing such sections, is increased.

6. In an apparatus of the class described, the combination of aninclosing casing, a horizontal partition for dividing the apparatus intotwo sections, means for feeding heated air into one of said sections,means for discharging heated air from the other of said sections, meansfor maintaining the temperature of the heated air when passing throughthe apparatus and for radiating heat rays, and means for increasing thevelocity of the molecules of the heated air during the time the body ofheated air is traversing said sections.

7. In an apparatus of the class described, i

the combination of an inclosing casing, a horizontal partition fordividing the apparatus into two sections, a passage way connected tolthe upper section, a passage way connected to the lower section, doorscontrolling said passage ways,an air supply duct connected to the upperpassage way, an exhaust blower connected to the lower section, and meansinterposed between the two sections at the end of the apparatus forGEORGE HILLARD BENJAMIN.

passing Witnesses:

HELEN E. KoELsoH, LESTER BEARDSLEY.

